A receiver/decoder also called IRD (Integrated Receiver Device) or set top box is a home appliance connected to an input signal for receiving television channels. The input signal can be of different types and provided by various sources such as satellite, terrestrial reception antenna, cable or IP connections.
The input signal is then processed by the IRD to tune or filter a channel requested by the user. The IRD is generally connected to a television set that allows a user watching displayed content of a selected television channel.
The IRD may also comprise recording capabilities generally on a hard disc and performs various tasks related to conditional access to the content. For that purpose, the IRD can be connected to a security module in charge of processing access rights messages, checking the access conditions and releasing keys authorizing access to the content.
The IRD can be in form of a module directly plugged into a connection slot of the television set, the input signal being first received and filtered (or tuned) by the television set and passed to the module which processes the access conditions and the decryption of the security layer.
The IRD is driven by a remote control allowing transmitting numerous user commands such as: selecting a channel, entering a password in case of parental control for example, activating an electronic program guide (EPG), managing user parameters and profiles, scheduling content recording, selecting various operations modes, etc.
The communication protocol between the IRD and the remote control being known, some manufacturers propose compatible remote controls having enhanced features such as driving a plurality of devices.
An IRD is not only used in a one way consumption device, but is also used in an interactive device to enter commands for ordering goods, to participate to a survey or simply to confirm the presence of the user. In this particular case, the document WO2009/109583 proposes a mechanism to reward a user for watching advertisements. This document describes the display of a pseudo-random character to ascertain that a real user is setting next to the television set rather than a modified remote control connected to a web site that automatically transmits the right answer to all connected remote controls without requiring the presence any user.